Malignant melanoma is a malignant neoplasm that arises from melanocytes (or cells that derive from melanocytes).
Melanocytes predominantly occur in the basal layer of the epidermis and most melanomas, therefore, arise in the skin. However, melanocytes do occur in other locations and can give rise to primary melanoma in unexpected locations, e.g. primary uveal malignant melanoma.
Thus, melanoma may be primary or metastatic and the primary form may arise from the skin, or (and much more infrequently) from other sites. Each is discussed separately:
- primary cutaneous melanoma
- primary noncutaneous melanoma
- metastatic melanoma
In general, radiology is useful for identifying metastatic melanomatous deposits.
Treatment and prognosis
Despite being one of the less common types of skin cancer, they cause the majority (75%) of skin-cancer-related deaths.